The secret is to simply let it be

Now that we've determined the most effective way to prevent the bubbles inside from bursting and dissipating is to keep the bottle as still as possible, the key to maintaining your Champagne's effervescence is simply to... let it be. Place your Champagne in the refrigerator and leave it there until you're ready to enjoy it again. This will help preserve the bubbles within the bottle—each one a pocket of carbon dioxide gas.
However, here's the surprising part: not only should you avoid putting a spoon in the bottle, but it might also be best not to re-cork it. Research from Stanford University found that re-corking the bottle can actually cause the Champagne to lose its fizz even faster than using a spoon. The most enjoyable bottle in their study was one that had not been sealed at all!
That said, take this information with a grain of caution, as the study noted that the sample size was relatively small. Therefore, there's a slight possibility that the findings may not be entirely reliable. Still, this approach is a far better strategy for keeping your Champagne bubbly than relying on the spoon method.
While you're at it, put it in the fridge, too

To maintain the effervescence of carbonated beverages like Champagne, it's essential to store them at lower temperatures. When the drink is chilled, the carbon dioxide gas that creates the bubbles remains more dissolved in the liquid, which helps prevent it from escaping too quickly. Conversely, as the Champagne warms, the solubility of carbon dioxide diminishes, resulting in gas release and a loss of its fizz.
Therefore, in addition to allowing your Champagne to rest undisturbed, keeping it cool is the next best step. A cooler environment significantly extends its freshness and effervescence compared to storing it at room temperature.
For optimal results, aim for an even lower temperature. If you plan to enjoy the Champagne the following day and want to keep it in excellent condition, consider placing the heavy bottle in an ice bucket. This method will keep the wine much cooler than the refrigerator without freezing it solid in the freezer. When you're ready to enjoy it, simply take it out and raise a well-deserved toast in a white wine glass (avoid using a flute) to celebrate the effort you put into keeping it fresh and delicious!
Recommended

The Ice Bucket Mistake To Avoid While Chilling Wine

Keep Champagne Fizzy For Up To 2 Weeks With A Special Stopper

The Best Wines To Sip With Brunch According To The Pros

How Does A Beer Get Skunky?
Next up